The Claim: Being Left-Handed Adds to the Risk of Migraines

Already burdened with the minor mishaps that arise from living in a world designed for righties, their lot in life seemed to worsen considerably in the 1980s, when a study argued that southpaws had several times the risk of chronic headaches — and immune disorders — as their right-handed counterparts. The reason, it was theorized, had something to do with variations in fetal brain development, though no precise explanation was given.

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Leif Parsons

But a raft of evidence now suggests that the migraine finding, though intriguing, was less fact than statistical artifact. A more extensive study published in March by German scientists examined a group of 100 patients who had received a diagnosis of migraine based on standards set by the International Headache Society. After finding no evidence of a link between handedness and migraines, the scientists pooled data from five other studies and conducted a meta-analysis. Still, there was no evidence of a relationship — a conclusion echoed by many similar studies.

Several studies have also examined whether there is any relationship between left-handedness and increased risk of immune disorders. The findings are inconclusive. Proponents argue that fetal exposure to high levels of testosterone could be responsible, and they point out that left-handedness is more common in men than women. Critics say more research is needed.

THE BOTTOM LINE Most studies have found that being left-handed does not increase the risk of migraines.